The present invention relates generally to oxygen top-blown converters and more particularly to a control method therefor wherein during the converter oxygen blowing operation a sensor is immersed in the steel bath to measure the temperature and carbon content of the steel bath, whereby on the basis of the measured values the steel bath temperature and carbon content at the end point of the oxygen blowing are simultaneously controlled.
In the past, known methods of the type designed to control the temperature and carbon content of molten steel at the end-point in oxygen top-blown converters are grouped into two broad classes; (1) those in which the temperature or carbon content of the steel bath is measured by a sensor immersed in the steel bath to simply control the temperature or carbon content at the end-point in accordance with the measured temperature or carbon content, and (2) those in which the temperature measurement is effected by means of a sensor immersed in the steel bath and the carbon content is measured by means of a separate sensor or from information obtained from other than the steel bath, e.g. the analysis of the waste gases, whereby to simultaneously control the temperature and carbon content of the steel bath at the end-point.
A disadvantage of the former methods is that these methods are after all the single control methods and therefore either the temperature or the carbon content at the end-point is controlled alone. A disadvantage of the latter methods is that due to the use of two or more sensors or the use of the information obtained from the analysis of waste gases, not only more equipment and labor are required, but also their successive use over a long period of time is difficult in consideration of the accuracy and maintenance of the instruments.